Rig mounted compactor

ABSTRACT

A rig mounted compactor is provided. The rig mounted compactor comprises a shaft rotatably arranged to cause vibration of the rig mounted compactor with a first amplitude and a second amplitude by means of a first weight and a second weight and a hydraulic motor arranged to drive the shaft. The first weight is eccentrically fixed to the shaft, and the second weight is eccentrically arranged at the shaft. The second weight is clutchable between an idle mode when driven in the direction, and a rotatable mode when driven in the direction. The second weight is arranged to idle with respect to the shaft in the idle mode. The shaft is arranged to cause the first amplitude of the vibration by the first weight in the idle mode, and the second weight is arranged to rotate synchronously with the shaft in the rotatable mode to cause the second amplitude of the vibration.

TECHNICAL FIELD

Embodiments herein relate to a rig mounted compactor.

BACKGROUND

Compactors are designed for compacting different grounds, such as soil, gravel or the like. A known compactor comprises a weight arranged on a rotatable shaft driven by a motor that may be an electrical motor, a hydraulic motor or a combustion engine. Rotation of the shaft and the weight arranged on the shaft generates centrifugal forces that cause vibrations. The vibrations are used for compacting the soil or gravel by the compactor. The compactor vibrates with an amplitude that depends on eccentricity of the weight with respect to the shaft and mass of the weight and on a rotational speed of the shaft.

Rig mounted compactors, usually hydraulically driven by for example an excavator, are designed for compacting soil, trenches and embankments as well as driving and pulling out posts and formwork. A rig mounted compactor offers increased safety in use as there is no need for a user to stand directly in a workspace of the compactor. Areas that are difficult to access for the user may be reached more easily by use of the rig mounted compactors.

A known rig mounted compactor is usually designed to work with different amplitudes, typically with two amplitudes. The rig mounted compactor typically comprises two eccentric weights arranged on a shaft and the amplitudes are changed by changing the direction of rotation of the shaft. In a first direction, the eccentric weights are arranged to rotate in phase to cause a first amplitude of vibration and in a second direction, being opposite to the first direction, the weights are arranged to rotate out of phase to thereby cause a second amplitude of vibration. The first amplitude is then higher than the second amplitude. The shaft is usually driven by a bi-directional hydraulic motor to capable of being driven such as to cause the weights to rotate in the first and second directions.

The motor is then connected to a complex flow control system arranged at for example the aforementioned excavator to control flow in a hydraulic system controlling the motor.

One problem with existing rig mounted compactors adapted to work with two amplitudes is that the rig mounted compactors are only compatible with a limited number of types of machines, such as the excavator above.

SUMMARY

An object of the embodiments herein is to provide a rig mounted compactor compatible with several types of machines.

According to an aspect of the present disclosure, the object is achieved by a rig mounted compactor comprising: a shaft rotatably arranged to cause vibration of the rig mounted compactor with a first amplitude and a second amplitude by means of a first weight and a second weight, a hydraulic motor arranged to drive the shaft, wherein the hydraulic motor is arranged to drive the shaft in a direction. The rig mounted compactor further comprises: the first weight eccentrically fixed to the shaft and the second weight eccentrically arranged at the shaft, wherein the second weight is clutchable between an idle mode when driven in the direction, and a rotatable mode when driven in the direction. The second weight is arranged to idle with respect to the shaft in the idle mode, wherein the shaft is arranged to cause the first amplitude of the vibration by the first weight in the idle mode, and wherein the second weight is arranged to rotate synchronously with the shaft in the rotatable mode to cause the second amplitude of the vibration.

Since the hydraulic motor is arranged to drive the shaft in the direction when the rig mounted compactor is operated with both the first and second amplitudes, a single-direction hydraulic motor may be used for driving the shaft. The single direction hydraulic motor is adapted to work, or operate, in only one and the same direction, referred to as the direction herein. Accordingly, the rig mounted compactor may be connected to a machine, such as an excavator, comprising a simple flow control system for control of flow in a hydraulic system controlling the hydraulic motor. The rig mounted compactor is thus compatible with several types of machines, such as machine with simple flow control system. As a result, the above mentioned object is achieved.

The first weight is eccentrically fixed to the shaft. In other words, the first weight is rigidly mounted on the shaft to rotate with the shaft at a same rotational speed as the shaft. Thus, rotation of the shaft always causes rotation of the first weight. Since the first weight is eccentrically fixed to the shaft rotation of the first weight causes centrifugal forces acting on the first weight and on the shaft, which centrifugal forces cause vibration of the rig mounted compactor.

The second weight is also eccentrically arranged at the shaft. Thus, rotation of the second weight also causes centrifugal forces acting on the second weight and the shaft, which centrifugal forces cause vibration of the rig mounted compactor.

Further, since the second weight is clutchable between the idle mode when driven in the direction and the rotatable mode when driven in the direction the second weight may be shifted between the idle mode and the rotatable mode. Advantageously, the second weight is shifted between the idle mode and the rotatable mode when the shaft is in a shaft position permitting shifting. Preferably, the shifting is performed when the shaft does not rotate.

In the idle mode, the second weight is arranged to idle with respect to the shaft. This means that the second weight is arranged to freely rotate on the shaft in a passive manner. The passive manner refers to that the second weight does not, in the idle mode, contribute to the vibration of the rig mounted compactor. Thereby, in the idle mode of said second weight, the vibration of the rig mounted compactor is caused mainly by the first weight, being eccentrically fixed to the shaft. Thus, in the idle mode of the second weight, the first amplitude of vibration is generated.

In the rotatable mode, the second weight is clutched to the shaft, i.e. the second weight is connected to the shaft to synchronously rotate with the shaft at the same rotational speed as the shaft. Thus, in the rotatable mode the second weight rotates with the shaft and with the first weight eccentrically fixed to the shaft. Thereby, the vibration is caused both by the first weight and by the second weight in the rotatable mode. As a result, the second amplitude of vibration is generated.

Further, because the hydraulic motor is arranged to drive the shaft in the direction and the second weight is clutchable between the idle mode when driven in the direction, and the rotatable mode when driven in the direction, both the first amplitude and the second amplitude are generated when the shaft rotates in said direction.

Weight for causing the vibration may consists of the first weight and the second weight. Thereby, the rig mounted compactor may only comprise the first weight and the second weight in terms of the weight rotating to cause vibration. Thus, the rig mounted compactor, having few rotatable weights, is robust.

Optionally, the first weight and the second weight are arranged to cause the second amplitude of the vibration to be double the first amplitude of the vibration. Thereby, the first amplitude of vibration may be essentially half of the second amplitude of vibration. This may be achieved by adapting masses and eccentricities of the first weight arranged on the shaft and the second weight arranged at the shaft. As a result, in the rig mounted compactor it is easy to achieve a doubled, or halved, amplitude of the vibration.

The second weight may be arranged to rotate in phase with the first weight in the rotatable mode. In effect, the second weight may rotate together with the first weight around the shaft with no time and position delay between the first weight and the second weight during rotation of the first weight and the second weight around the shaft. Thereby, the rotatable mode is robust.

In some embodiments, the second weight may be clutchable by means of a clutch assembly, wherein the rig mounted compactor comprises the clutch assembly being arranged to connect the second weight to the shaft in the rotatable mode and arranged to disconnect the second weight from the shaft in the idle mode. Thereby, the clutch assembly connects and disconnects the second weight to/from the shaft by allowing a user to simply clutch the clutch assembly, e.g. by means of a lever, a handle or the like.

In these embodiments, the clutch assembly comprises: a sleeve, having a through-hole for receiving the shaft, freely rotatably arranged at the shaft, wherein the sleeve is fixedly arranged at the second weight, a connection member displaceably arranged in an opening provided in the sleeve, and a control member arranged to displace the connecting member between a disconnected position and a connected position. In this manner, position of the connecting member may be changed, e.g. displaced simply by using the control member, such as the lever, the handle or the like as mentioned above.

Additionally, in these embodiments, the second weight is in the idle mode when the connecting member is in the disconnected position, and the second weight is in the rotatable mode when the connecting member is in the connected position. As a result, the second weight may be switched, shifted, clutched or the like, between the idle mode and the rotatable mode simply by displacing the connecting member between the disconnected position and the connected position by the control member.

Moreover, in these embodiments, the shaft comprises a cavity arranged at an outer surface of the shaft, wherein the connection member is received by the cavity in the connected position and wherein the connection member is extracted from the cavity in the disconnected position. Thereby, rotational movement of the shaft may be transmitted to the second weight simply by receiving the connection member by the cavity arranged at the outer surface of the shaft in said connected position. Further, a transmission of the rotational movement of the shaft to the second weight may be stopped simply by extracting the connection member from the cavity in said disconnected position.

Accordingly, the clutch assembly may be robust, because the clutch assembly is arranged to disconnect the second weight from the shaft in the idle mode in a simple manner as explained above.

As a consequence, the rig mounted compactor is also made more robust thanks to that the second weight may be clutchable in a simple manner.

Furthermore, in some embodiments, the sleeve is provided with at least three openings including the opening. The at least three openings are arranged along a first cross-section of the sleeve. Further, the shaft comprises at least three cavities, including the cavity, wherein the at least three cavities are arranged along a second cross-section of the shaft. The at least three openings are unequally spaced along the first cross-section of the sleeve and wherein the at least three cavities are unequally spaced along the second cross-section of the shaft. Expressed differently, the at least three openings are spaced from each other with different angles therebetween with respect to a center point, or axis, of the sleeve. In a similar way, said at least three cavities are spaced from each other with different angles therebetween with respect to a center point, or axis, or the shaft. Said at least three openings comprises a first, a second and a third opening and said at least three cavities comprises a first cavity, a second cavity and a third cavity. An angle between the first opening and the second opening is essentially equal to a further angle between the first cavity and the second cavity. Further, the angle between the second opening and the third opening is essentially equal to the angle between the second cavity and the third cavity. In effect, it is in only one position of the shaft relatively the sleeve that each of said at least three cavities matches a corresponding one of said at least three openings. Thereby, positioning of the shaft in relation to the sleeve to a desired position is unambiguous, since should there be equal spacing between the cavities and the openings, it would be possible to lock the second weight and the sleeve to the shaft in three different positions, yielding a respective amplitude of vibration. Since the position in which the second weight is locked to shaft is not visible, or distinguishable, to the user, it would be dubious to the user which amplitude will be generated, should the cavities/openings be evenly spaced.

The clutch assembly comprises at least three connection members, including the connection member, and wherein each of the at least three connection members is received by a respective one of the at least three cavities in a respective connected position and wherein each of the at least three connection members is extracted from a respective one of the at least three cavities in a respective disconnected position. Thus, the second weight is connected to the shaft in a more secure way than if only one connection member is used. Further, a reliable and robust transmission of torque from the shaft to the second weight is achieved by said at least three connection members.

In a particular embodiment, the at least three openings are spaced from each other with 110 degrees and 150 degrees, and the at least three cavities are spaced from each other with 110 degrees and 150 degrees. Thereby, an even transmission of torque from the shaft to the second weight is achieved while at the same time only one and unambiguous position in which the second weight may be locked to the shaft is obtained.

Further features of, and advantages with, the embodiments herein will become apparent when studying the appended claims and the following detailed description. Those skilled in the art will realize that the different features described may be combined to create embodiments other than those described in the following, without departing from the scope of the embodiments herein, as defined by the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The various aspects of the embodiments herein, including its particular features and advantages, will be readily understood from the following detailed description and the accompanying drawings, in which:

FIG. 1 is a perspective view illustrating a rig mounted compactor arranged at an excavator,

FIG. 2 is a plan view illustrating the rig mounted compactor illustrated in FIG. 1,

FIG. 3 is another plan view illustrating a shaft, a first weight and a second weight of the compactor illustrated in FIG. 1 and FIG. 2, and

FIG. 4 is a further plan view illustrating the shaft, the first weight and the second weight illustrated in FIG. 3.

DETAILED DESCRIPTION

The embodiments herein will now be described more fully with reference to the accompanying drawings, in which example embodiments are shown. Disclosed features of example embodiments may be combined. Like numbers refer to like elements throughout. Well-known functions or constructions will not necessarily be described in detail for brevity and/or clarity.

FIG. 1 illustrates a compactor 1 mounted at a boom 4 of an excavator 2. The boom 4 may also be called a rig. Therefore, the compactor 1 is sometimes referred to as a rig mounted compactor. The rig mounted compactor 1 is detachably mounted at the boom 4 by an attaching means 6. The excavator 2, the boom 4 as well as the attaching means 6 are known constructions in the field of excavators. Hence, these constructions are not described in detail herein. The rig mounted compactor 1 may also be attached to other machines, such as a backhoe.

FIG. 2 illustrates the rig mounted compactor 1 in FIG. 1. The rig mounted compactor 1 comprises a shaft 3 rotatably arranged to cause vibration of the rig mounted compactor 1 with a first amplitude and a second amplitude by means of a first weight 5 and a second weight 7. The rig mounted compactor 1 comprises shaft bearings arranged at each end of the shaft 3 to enable rotation of the shaft 3 within the rig mounted compactor 1. Each of the shaft bearings may be any suitable kind of bearing, such as ball bearing, needle bearing or the like. For example spherical ball bearings for vibratory applications may be used. The shaft 3 is connected to a hydraulic motor 9 arranged to drive the shaft 3. The hydraulic motor 9 is connected to a hydraulic block (not shown) of a machine by means of hydraulic hoses 8.

FIG. 3 shows the shaft 3, the first weight 5 and the second weight 7 of the compactor illustrated in FIG. 1 and FIG. 2. In FIG. 3, the second weight 7 is illustrated in an idle mode. The shaft 3 comprises a seat 10 arranged to connect the shaft 3 to the hydraulic motor 9 illustrated in FIG. 2. The hydraulic motor 9 is arranged to drive the shaft 3 in a direction d, illustrated as being clockwise in FIG. 3. The direction d may in other examples be counter-clockwise.

The first weight 5 is eccentrically fixed to the shaft 3. The term “eccentrically” refers to that the first weight 5 is arranged on the shaft 3 so that a first mass center 12 of the first weight 5 is spaced a first distance r1 from a rotational axis Ar of the shaft 3. The first distance r1 may be in a range of 30 to 65 mm, for example about 46 mm, for example 46.5 mm The first distance r1 depends on a size of the compactor 1 and on desired vibration forces to be achieved by the compactor 1. According to the embodiment illustrated in FIG. 3, the first weight 5 is shaped as a half circle comprising a first hole with a center 16 of the hole being located on said rotational axis Ar when the first weight 5 is mounted on the shaft 3. The first weight 5 may be made of steel or the like. Mass of the first weight 5 depends on a size of the compactor 1 and on desired vibration forces to be achieved by the compactor 1. The mass of the first weight 5 may for example be about 7 kg, for example 6.94 kg. The first weight 5 is fixed to the shaft 3 for example by a process of heat fitting to rigidly mount the first weight 5 on the shaft 3. Thus, before heating the first weight 5 to fit it onto the shaft 3, a diameter of the first hole may be slightly smaller than a diameter dl of the shaft 3 at an area of the shaft 3 where the first weight 5 is intendent to be mounted. Explicitly, the diameter of the first hole is smaller than the diameter of the shaft 3 when the first weight 5 is cold in comparison to when being heat fitted.

The second weight 7 is also eccentrically arranged at the shaft 3, which means that the second weight 7 is arranged on the shaft 3 so that a second mass center 14 of the second weight 7 is spaced a second distance r2 from the rotational axis Ar of the shaft 3. The second distance r2 may be in a range of 30 to 65 mm, for example about 45 mm, for example 45.2 mm. Similar to the first distance r1, the second distance r2 depends on a size of the compactor 1 and on desired vibration forces to be achieved by the compactor 1. According to the embodiment illustrated in the FIG. 3, the second weight 7 has a shape similar to the first weight 5, i.e. the shape of a half circle comprising a second hole with the same hole center 16 that is located on said rotational axis Ar when the second weight 7 is mounted on the shaft 3. The first weight 5 and the second weight 7 may be for example be made of steel or the like. Similar to the mass of the first weight 5, mass of the second weight 7 depends on a size of the compactor 1 and on desired vibration forces to be achieved by the compactor 1. The mass of the second weight 7 may for example be about 7 kg, for example 6.56 kg.

According to the embodiment illustrated in FIG. 3, a bearing 18 is arranged between the shaft 3 and the second weight 7. The bearing 18 is fitted between the shaft 3 and the second weight 7 to enable the second weight 7 to idle on the shaft 3. The bearing 18, shown in FIG. 3, is a ball bearing. However, the bearing 18 may be another type of bearing, e.g. needle bearing or the like.

The second weight 7 is clutchable between the idle mode when driven in the direction d, and a rotatable mode when driven in the direction d. In the idle mode, the second weight 7 is arranged to idle with respect to the shaft 3. Idling of the second weight 7 may be achieved by freely rotating the second weight 7 on the bearing 18. Further, the second weight 7 is arranged to rotate synchronously with the shaft 3 in the rotatable mode shown in FIG. 4.

Since the first weight 5 is eccentrically fixed to the shaft 3 and the second weight 7 is eccentrically arranged at the shaft 3, a rotation of the first weight 7 and the second weight 7 causes centrifugal forces acting on the first weight 5 and the second weight 7 and on the shaft 3, which centrifugal forces cause vibration of the rig mounted compactor.

When the second weight 7 is in the idle mode, as illustrated in FIG. 3, the shaft 3 is arranged to cause the first amplitude of the vibration. The first amplitude of the vibration is accordingly caused by that the shaft 3 rotates the first weight 5, being eccentrically fixed to the shaft 3.

The shaft 3 is arranged on previously mentioned shaft bearings 28 arranged at each end of the shaft 3 to enable rotation of the shaft 3 within the rig mounted compactor.

The second weight 7 is clutchable by means of a clutch assembly 11. The rig mounted compactor 1 comprises the clutch assembly 11 being arranged to connect the second weight 7 to the shaft 3 in the rotatable mode and arranged to disconnect the second weight 7 from the shaft 3 in the idle mode.

According to the embodiment illustrated in FIG. 3, the clutch assembly 11 comprises a sleeve 13, having a through-hole 15 for receiving the shaft 3. The sleeve 13 is freely rotatably arranged at the shaft 3 and fixedly arranged at the second weight 7.

Further, the clutch assembly 11 comprises three connection members 17 displacably arranged in a respective opening 19 of three openings provided in the sleeve 13, and a control member 21 arranged to displace the connecting members 17 between a disconnected position p1 and a connected position p2. The disconnected position p1 and the connected position p2 are different positions of the connecting member 17 along a radial direction in relation to the axis Ar. In FIG. 3 the connecting members 17 are illustrated in the disconnected position p1. When the connecting members 17 are in the disconnected position p1, the second weight 7 is in the idle mode. For simplicity, appropriate reference numerals have only been provided for one connection member 17 and one opening 19.

The connecting members 17 may be balls made of steel, such as spherical balls. The connecting member 17 may have other forms and comprise other materials suitable for the purpose of the connecting members 17, as for example graphite.

The control member 21 is arranged to be displaced between an open position z1 and a closed position z2, wherein in the open position z1 of the control member 21 the connecting members 17 are in the disconnected position p1 and in closed position z2 of the control member 21 the connecting members 17 are in the connected position p2. The open position z1 and the closed position z2 are different positions of the control member along an axial direction in relation to the axis Ar.

The control member 21 is displaced by for example a lever or a handle (not shown) in FIG. 3. The lever or the handle may be connected to a connecting portion 20 of the control member 21. The control member 21 may be displaced between the open position z1 and the closed position z2 by using hand power from an operator or by a mechanic power from a motor acting on said lever or handle.

The shaft 3 in FIG. 3 and FIG. 4 comprises three cavities 23 arranged at an outer surface 26 of the shaft 3. Each of the three connection members 17 is received by a respective one of the three cavities 23 in a respective connected position p2 and each of the three connection members 17 is extracted from a respective one of the three cavities 23 to a respective disconnected position p1 during rotation of the shaft 3. In FIG. 3, the three connection members 17 are extracted from a respective one of the three cavities 23.

Each of the three cavities 23 comprises a first edge 22 and a second edge 24. The first edge 22 has a higher inclination than the second edge 24 relatively the outer surface 26 of the shaft 3. Thus, in said connected position p2, each of the three connecting members 17 is held in a respective cavity 23 by the control member 21, being in the closed position z2, and abuts the first edge 22 especially during rotation of the shaft 3 in the direction d which causes rotation of the sleeve 13 and rotation of the second weight 7 in the rotatable mode of the second weight 7.

When the control member 21 is in the open position z1, each of the three connecting members 17 is extracted from a respective one of the three cavities 23 to a respective disconnected position p1 during rotation of the shaft in the direction d. This may be achieved by forces caused by the edge 22 acting on the connecting member 17 during rotation of the shaft 3 in the direction d. In this manner, each of the three connecting members 17 is displaced to the disconnected position p1 during rotation of the shaft 3 in the direction d when the second weight 7 is in the idle mode.

Further, as illustrated in FIG. 3 and FIG. 4, the sleeve 13 is provided with three openings 19, wherein the three openings 19 are arranged along a first cross-section of the sleeve 13. The shaft 3 comprises three cavities 23 wherein the three cavities 23 are arranged along a second cross-section of the shaft 3, and wherein the three openings 19 are unequally spaced along the first cross-section of the sleeve 13 and wherein the three cavities 23 are unequally spaced along the second cross-section of the shaft 3. The first cross section of the sleeve 13 and the second cross-section of the shaft 3 coincide with each other when the sleeve 13 is mounted on the shaft 3. FIG. 3 and FIG. 4 illustrate the sleeve 13 mounted on the shaft 3.

Expressed differently, the three openings 19 are spaced from each other with different angles α and β therebetween with respect to the center 16 of the sleeve. In a similar way the three cavities 23 are also spaced from each other with the angles α and β therebetween with respect to a center point of the shaft 3.

Thereby, positioning of the shaft 3 in relation to the sleeve 13 to a desired position is unambiguous as explained above. The shaft 3 and the sleeve 13 may then be positioned to enable rotation of the second weight 7 in phase with the first weight 5 in the rotatable mode of the second weight 7.

The angle α may be in a range of 100-120 degrees, for example 110 degrees and the angle β may be in a range of 140-160 degrees, for example 150 degrees.

FIG. 4 shows the shaft 3, the first weight 5 and the second weight 7 illustrated in FIG. 3 when the second weight 7 is in the rotatable mode. As can be seen from the Figure, the connecting member 17 is displaced to the connected position p2 by the control member 21 displaced to the closed position z2.

In the rotatable mode of the second weight 7, the first weight 5 and the second weight 7 are arranged to cause the second amplitude of the vibration. The second amplitude of vibration is achieved by simultaneous rotation of the first weight 5 and the second weight 7 in the rotatable mode. The first weight 5 and the second weight 7 are adapted to cause the second amplitude in the rotatable mode, wherein the second amplitude is double or twice the first amplitude. This may be achieved by adapting masses and distances r1 and r2 of the first and second weights 5, 7.

Accordingly, the rig mounted compactor 1 may be connected to a machine, such as an excavator, comprising a simple flow control system for control of flow in a hydraulic system controlling the hydraulic motor. The simple flow control system may, for example, lack a drain line, which otherwise often is needed in order to drive and operate existing rig mounted compactors. 

1. A rig mounted compactor comprising: a shaft rotatably arranged to cause vibration of said rig mounted compactor with a first amplitude and a second amplitude by means of a first weight and a second weight, a hydraulic motor arranged to drive said shaft, wherein said hydraulic motor is arranged to drive said shaft in a direction, and wherein said rig mounted compactor comprises: said first weight, being eccentrically fixed to said shaft, and said second weight, being eccentrically arranged at said shaft, wherein said second weight is clutchable between an idle mode when driven in said direction, and a rotatable mode when driven in said direction, wherein said second weight is arranged to idle with respect to said shaft in said idle mode, wherein said shaft is arranged to cause the first amplitude of the vibration by said first weight in said idle mode, and wherein said second weight is arranged to rotate synchronously with said shaft in said rotatable mode to cause the second amplitude of the vibration.
 2. The rig mounted compactor according to claim 1, wherein weight for causing the vibration consists of the first weight and the second weight.
 3. The rig mounted compactor according to claim 1, wherein said first weight and said second weight are arranged to cause said second amplitude of the vibration to be double said first amplitude of the vibration.
 4. The rig mounted compactor according to claim 1, wherein said second weight is arranged to rotate in phase with said first weight in said rotatable mode.
 5. The rig mounted compactor according to claim 1, wherein the second weight is clutchable by means of a clutch assembly, wherein the rig mounted compactor comprises said clutch assembly being arranged to connect said second weight to said shaft in said rotatable mode and arranged to disconnect said second weight from said shaft in said idle mode.
 6. The rig mounted compactor according to claim 5, wherein said clutch assembly comprises: a sleeve, having a through-hole for receiving said shaft, freely rotatably arranged at said shaft, wherein said sleeve is fixedly arranged at said second weight, a connection member displacably arranged in an opening provided in said sleeve, and a control member arranged to displace said connecting member between a disconnected position and a connected position, wherein said second weight is in said idle mode when said connecting member is in said disconnected position, and wherein said second weight is in said rotatable mode when said connecting member is in said connected position, wherein said shaft comprises a cavity arranged at an outer surface of said shaft, wherein said connection member is received by said cavity in said connected position and wherein said connection member is extracted from said cavity in said disconnected position.
 7. The rig mounted compactor according to claim 6, wherein said sleeve is provided with at least three openings including said opening, wherein said at least three openings are arranged along a first cross-section of said sleeve, and wherein said shaft comprises at least three cavities, including said cavity, wherein said at least three cavities are arranged along a second cross-section of said shaft, and wherein said at least three openings are unequally spaced along said first cross-section of said sleeve and wherein said at least three cavities are unequally spaced along said second cross-section of said shaft, and wherein said clutch assembly comprises at least three connection members, including said connection member, and wherein each of said at least three connection members is received by a respective one of said at least three cavities in a respective connected position and wherein each of said at least three connection members is extracted from a respective one of said at least three cavities in a respective disconnected position.
 8. The rig mounted compactor according to claim 7, wherein said at least three openings are spaced from each other with 110 degrees and 150 degrees, and said at least three cavities are spaced from each other with 110 degrees and 150 degrees. 